In chemistry, the history of the molecule traces the origins of the concept or idea of the existence, in nature, of a bonded structure of two or more atoms, according to which the structures of the universe are built. In a sense, the concept of united atoms, i.e. molecules, traces it origins back the 5th century BC views of the Greek philosopher Leucippus who argued that all the universe is composed of atoms and voids. In about 450 BC, the Greek Empedocles introduced the idea of the four "roots" of things: fire, air, water, and earth; and two "forces", attraction and repulsion, which function to join and separate the four roots. Thus, it can be argued that, from this point onward, people have speculated as to how atoms or roots might unite in combination. Chemistry (from Greek χημεία khemeia[1] meaning alchemy) is the science of matter at the atomic to molecular scale, dealing primarily with collections of atoms, such as molecules, crystals, and metals. ... In chemistry, a molecule is an aggregate of at least two atoms in a definite arrangement held together by special forces. ... Galunggung in 1982, showing a combination of natural events. ... Properties In chemistry and physics, an atom (Greek ἄτομος or átomos meaning indivisible) is the smallest particle of a chemical element that retains its chemical properties. ... The deepest visible-light image of the cosmos, the Hubble Ultra Deep Field. ... This article is about the philosopher. ... Empedocles of Agrigentum Empedocles (Greek: Εμπεδοκλής, circa 490 BCE – c. ...

Water H₂O the world's most famous "molecule"

3D orbital-view of the H₂O.

Image File history File links Download high-resolution version (1100x481, 42 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Water (molecule) ... Image File history File links Download high-resolution version (1100x481, 42 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Water (molecule) ... Water is a tasteless, odourless substance that is essential to all known forms of life and is known as the universal solvent. ... Image File history File links Download high-resolution version (1100x1030, 166 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Water (molecule) User:Benjah-bmm27/Gallery User:Ben Mills/Gallery User:Benjah-bmm27/Gallery/Hydrogen ... Image File history File links Download high-resolution version (1100x1030, 166 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Water (molecule) User:Benjah-bmm27/Gallery User:Ben Mills/Gallery User:Benjah-bmm27/Gallery/Hydrogen ... Electron atomic and molecular orbitals In quantum chemistry (electronic structure theory), the molecular electronic states, i. ... This article describes water from a scientific and technical perspective. ...

Etymology

According to Merriam-Webster and the Online Etymology Dictionary, the word "molecule" derives from the Latin "moles" or small unit of mass, which is akin to the Greek molos, meaning exertion (c.1548) possibly referring to fact that it takes a certain amount of exertion effort to lift a small mass; or specifically: Merriam-Webster, originally known as the G. & C. Merriam Company of Springfield, Massachusetts, is a United States company that publishes reference books, especially dictionaries that are descendants of Noah Websters An American Dictionary of the English Language (1828). ... The Online Etymology Dictionary is an online etymological dictionary. ... Latin is an ancient Indo-European language originally spoken in Latium, the region immediately surrounding Rome. ... The mole (symbol: mol) is the SI base unit that measures an amount of substance. ...

Molecule (1794) - "extremely minute particle," from Fr. moléclue (1678), from Mod.L. molecula, dim. of L. moles "mass, barrier". A vague meaning at first; the vogue for the word (used until late 18th century only in Latin form) can be traced to the philosophy of Descartes.

René Descartes René Descartes (IPA: , March 31, 1596 – February 11, 1650), also known as Cartesius, worked as a philosopher and mathematician. ...

Early views

Prior to the development of the concept of the "molecule" were the various essential element theories. In the early 6th century BC, the Greek scientist Thales of Miletus reasoned that essential element was water and that all things derived from this element. According to legend, Thales was walking along a hillside path on the shore of Ionia, in what is now called south-western Turkey, and he noticed some rocks which contained fossils of what were unmistakably seashells. This led Thales to believe that the hills must have once been part of the sea. On this logic, Thales reasoned that the original world must have been entirely water, and that this was the essential element. For the French electronics and defence contractor, see Thales Group Thales (in Greek: Θαλης) of Miletus (circa 635 BC - 543 BC), also known as Thales the Milesian, was a pre-Socratic Greek philosopher and one of the Seven Sages of Greece. ... Water is a tasteless, odourless substance that is essential to all known forms of life and is known as the universal solvent. ... Ionia (Greek Ιωνία; see also List of traditional Greek place names) was an ancient region of southwestern coastal Anatolia (now in Turkey) on the Aegean Sea. ...

In the 5th century BC, the Greek Empedocles, being influenced by Pythagoras, claimed that all things consisted of differing combinations of four elements: Empedocles of Agrigentum Empedocles (Greek: Εμπεδοκλής, circa 490 BCE – c. ... Pythagoras of Samos (Greek: Πυθαγόρας; circa 582 BC – circa 507 BC) was an Ionian (Greek) mathematician and philosopher, founder of the mystic, religious and scientific society called Pythagoreans. ...

Adding to the four elements of the Greeks, in about 350 BC, Aristotle both coined the term “element” and conceived of a fifth element called "quintessence", which formed the heavens. Building on this logic, various writers over the years have speculated on possible geometric shapes, such as circles, squares, and polygons, etc., of elements and how these shapes might combine, separate, or possibly rub against each other to create new elements over evolutionary periods. Image File history File links Description: The four classical elements, after Aristotle. ... Several ancient Classical Element ideas exist. ... Aristotle (Greek: AristotélÄ“s) (384 BC – March 7, 322 BC) was an ancient Greek philosopher, a student of Plato and teacher of Alexander the Great. ... The word quintessence is used in different fields: In physics, quintessence is a hypothetical form of energy postulated to exist as a possible explanation of observations of an accelerating universe. ...

17th century

One of the earliest molecular theories was that put forward by the famous French naturalist Rene Descartes who believed that some atoms were furnished with hook-like projections, and others, with eye-like ones. He held that two atoms combined when the hook of one got caught in the eye of the other, such as shown below: René Descartes René Descartes (IPA: , March 31, 1596 – February 11, 1650), also known as Cartesius, worked as a philosopher and mathematician. ...

Mock-up of Rene Descartes' "Hook-and-Eye" bonding Model (c.1625)

In a more concrete manner, however, the concept of aggregates or units of bonded atoms, i.e. "molecules", traces its origins to Robert Boyle's 1661 hypothesis, in his famous treatise The Sceptical Chymist, that matter is composed of clusters of particles and that chemical change results from the rearrangement of the clusters. Boyle argued that matter's basic elements consisted of various sorts and sizes of particles, called "corpuscles", which were capable of arranging themselves into groups. René Descartes René Descartes (IPA: , March 31, 1596 – February 11, 1650), also known as Cartesius, worked as a philosopher and mathematician. ... Robert Boyle Robert Boyle (January 25, 1627–December 30, 1691) was an Irish natural philosopher (chemist, physicist, and inventor) noted for his work in physics and chemistry. ...

18th century

An early precursor to the idea of bonded "combinations of atoms", was the theory of "combination via chemical affinity". For example, in 1718, building on Boyle’s conception of combinations of clusters, the French chemist Étienne François Geoffroy developed theories of chemical affinity to explain combinations of particles, reasoning that a certain alchemical “force” draws certain alchemical components together. Geoffroy's name is best known in connection with his tables of "affinities" (tables des rapports), which he presented to the French Academy in 1718 and 1720. Chemical affinity results from electronic properties by which dissimilar substances are capable of forming chemical compounds. ... Étienne François Geoffroy (February 13, 1672 - January 6, 1731), French chemist, was first an apothecary and then practised medicine. ... Chemical affinity results from electronic properties by which dissimilar substances are capable of forming chemical compounds. ... Chemical affinity results from electronic properties by which dissimilar substances are capable of forming chemical compounds. ... The Académie française (French Academy) is the pre-eminent French learned body on matters pertaining to the French language. ...

Étienne François Geoffroy’s 1718 Affinity Table: at the head of the column is a substance with which all the substances below can combine.

These were lists, prepared by collating observations on the actions of substances one upon another, showing the varying degrees of affinity exhibited by analogous bodies for different reagents. These tables retained their vogue for the rest of the century, until displaced by the profounder conceptions introduced by CL Berthollet. In 1789, William Higgins published views on what he called combinations of "ultimate" particles, which foreshadowed the concept of valency bonds. If, for example, according to Higgins, the force between the ultimate particle of oxygen and the ultimate particle of nitrogen were 6, then the strength of the force would be divided accordingly, and similarly for the other combinations of ultimate particles: Étienne François Geoffroy (February 13, 1672 - January 6, 1731), French chemist, was first an apothecary and then practised medicine. ... A reagent or reactant is any substance used in a chemical reaction. ... Claude Louis Berthollet Claude Louis Berthollet (December 9, 1748 – November 6, 1822) was a French chemist. ... Now the LTTE has been devided into two part, I want to know about wanni Party and Karuna Party. specialy International affaires about this two party. ...

William Higgins' combinations of ultimate particles (1789)

Now the LTTE has been devided into two part, I want to know about wanni Party and Karuna Party. specialy International affaires about this two party. ...

19th century

Similar to these views, in 1803 John Dalton took the atomic weight of hydrogen, the lightest element, as unity, and determined, for example, that the ratio for nitrous anhydride was 2 to 3 which gives the formula N₂O₃. Interestingly, Dalton incorrectly imagined that atoms “hooked” together to form molecules. Later, in 1808, Dalton published his famous diagram of combined "atoms": John Dalton John Dalton (September 6, 1766 – July 27, 1844) was an English chemist and physicist, born at Eaglesfield, near Cockermouth in Cumberland. ...

John Dalton's union of atoms combined in ratios (1808)

In Amedeo Avogadro's famous 1811 paper "Essay on Determining the Relative Masses of the Elementary Molecules of Bodies", he essentially states, i.e. according to Partington's A Short History of Chemistry, that:^[1] John Dalton John Dalton (September 6, 1766 – July 27, 1844) was an English chemist and physicist, born at Eaglesfield, near Cockermouth in Cumberland. ... Portrait of Amedeo Avogadro Lorenzo Romano Amedeo Carlo Avogadro, Count of Quaregna and Cerreto (August 9, 1776–July 9, 1856) was an Italian chemist, most noted for his contributions to the theory of molarity and molecular weight. ... Partington is a village and civil parish in the Metropolitan Borough of Trafford in Greater Manchester, England. ...

The smallest particles of gases are not necessarily simple atoms, but are made up of a certain number of these atoms united by attraction to form a single molecule.

It must be noted here that this quote is a literal translation. Avogadro uses the name "molecule" for both atoms and molecules. Specifically, he uses the name "elementary molecule" when referring to atoms and to complicate the matter also speaks of "compound molecules" and "composite molecules". Image File history File links Cquote1. ... Image File history File links Cquote2. ...

During his stay in Vercelli Avogadro wrote a concise note (memoria) in which he declared the hypothesis of what we now call Avogadro's law: equal volumes of gases, at the same temperature and pressure, contain the same number of molecules. This law implies that the relationship occurring between the weights of same volumes of different gases, at the same temperature and pressure, corresponds to the relationship between respective molecular weights. Hence, relative molecular masses could now be calculated from the masses of gas samples. In 1811 Amedeo Avogadro stated the hypothesis which we now call Avogadros law: (See: this site for an English translation of his 1811 paper). ... The molecular mass of a substance (less accurately called molecular weight and abbreviated as MW) is the mass of one molecule of that substance, relative to the unified atomic mass unit u (equal to 1/12 the mass of one atom of carbon-12). ...

Avogadro developed this hypothesis in order to reconcile Joseph Louis Gay-Lussac's 1808 law on volumes and combining gases with Dalton's 1803 atomic theory. The greatest difficulty Avogadro had to resolve was the huge confusion at that time regarding atoms and molecules – one of the most important contributions of Avogadro's work was clearly distinguishing one from the other, admitting that simple particles too could be composed of molecules, and that these are composed of atoms. Dalton, by contrast, did not consider this possibility. Curiously, Avogadro considers only molecules containing even numbers of atoms; he does not say why odd numbers are left out? Joseph Louis Gay-Lussac. ... The Law of Charles and Gay-Lussac (frequently called simply Charles Law) is one of the gas laws, and relates the volume and temperature of an ideal gas held at a constant pressure. ... Various atoms and molecules as depicted in John Daltons A New System of Chemical Philosophy (1808). ...

In 1826, building on the work of Avogadro, the French chemist Jean-Baptiste Dumas states: Jean Baptiste Andr Dumas Jean Baptiste Andr Dumas (July 14, 1800 - April 10, 1884), French chemist, best known for his works on organic analysis and synthesis, as well as the determination of atomic weights (relative atomic masses) by measuring vapor densities. ...

Gases in similar circumstances are composed of molecules or atoms placed at the same distance, which is the same as saying that they contain the same number in the same volume.

In coordination with these concepts, in 1833 the french chemist Marc-Antoine-Auguste Gaudin presented a clear account of Avogadro's hypothesis, regarding atomic weights, by making use of “volume diagrams”, which clearly show both semi-correct molecular geometries, such as a linear water molecule, and correct molecular formulas, such as H₂O: Image File history File links Cquote1. ... Image File history File links Cquote2. ...

Marc-Antoine-Auguste Gaudin's volume diagrams of molecules in the gas phase (1833)

In 1863, an unknown Vienna high-school teacher named Joseph Loschmidt published, at his own expense, a booklet entitled Chemische Studine I, containing pioneering molecular images which showed both "ringed" structures as well as double-bonded structures, such as:^[2] Jan or Johann Josef Loschmidt (March 15, 1821 - July 8, 1895) who referred to himself mostly as Josef Loschmidt (omitting his first name), was a notable Austrian scientist with groundbreaking work in the fields of chemistry and physics (thermodynamics, optics, electrodynamics). ...

Joseph Loschmidt's molecule drawings of ethylene H₂C=CH₂ and acetylene HC=CH (1861)

It is argued that Loschmidt's ringed molecular images formed the seed of thought for August Kekule's story of how he "dreamed up" the benzene ring structure. An often-repeated story claims that after years of studying carbon bonding, benzene and related molecules, he dreamt one night of the Ouroboros, a snake eating its own tail, and that upon waking he was inspired to deduce the ring structure of benzene. The story, however, first appeared in the Berichte der Durstigen Chemischen Gesellschaft (Journal of the Thirsty Chemical Society), a parody of the Berichte der Deutschen Chemischen Gesellschaft, which appeared annually in the late-19th century on the occasion of the congress of German chemists; as such, it is probably to be treated with circumspection. Jan or Johann Josef Loschmidt (March 15, 1821 - July 8, 1895) who referred to himself mostly as Josef Loschmidt (omitting his first name), was a notable Austrian scientist with groundbreaking work in the fields of chemistry and physics (thermodynamics, optics, electrodynamics). ... Ethylene (or IUPAC name ethene) is the chemical compound with the formula CH2CH2. ... Acetylene (IUPAC name: ethyne) is the simplest alkyne hydrocarbon, consisting of two hydrogen atoms and two carbon atoms connected by a triple bond. ... Friedrich August Kekul von Stradonitz (September 7, 1829 - July 13, 1896) was a German organic chemist. ... Benzene, also known as benzol, is an organic chemical compound with the formula C6H6. ... An image drawn in 1478 by one Theodoros Pelecanos in an alchemical tract entitled Synosius. ... For other uses, see Snake (disambiguation). ... In contemporary usage, a parody is a work that imitates another work in order to ridicule, ironically comment on, or poke affectionate fun at the work itself, the subject of the work, the author or fictional voice of the parody, or another subject. ...

While his (more formal) claims were well-publicized and accepted, biographers came to the conclusion that Kekulé's understanding of the tetravalent nature of carbon bonding depended on the previous research of Archibald Scott Couper and Josef Loschmidt. The cyclic nature of benzene was finally confirmed by the eminent crystallographer Kathleen Lonsdale. Benzene presents a special problem in that, to account for all the bonds, there must be alternating double carbon bonds: Archibald Scott Couper (1831-1892) was the author of On a New Chemical Theory, Philosophical Magazine 16, 104-116 (1858) [as excerpted in Alembic Club Reprint #21, On a New Chemical Theory and Researches on Salicylic Acid[1]] Friedrich August Kekulé von Stradonitz claimed to solve the structure of Benzene... Johann Josef Loschmidt (March 15, 1821 - July 8, 1895) was an Austrian physicist and chemist. ... Dame Kathleen Lonsdale (January 28, 1903 - April 1, 1971) was a prominent crystallographer, who discovered the planar hexagonal structure of benzene. ... Covalent bonding is a form of chemical bonding characterized by the sharing of one or more pairs of electrons between atoms, in order to produce a mutual attraction, which holds the resultant molecule together. ...

Benzene molecule with alternating double bonds

The year 1873, by many accounts, was a seminal point in the history of the development of the concept of the "molecule". In this year, the renowned Scottish physicist James Clerk Maxwell published his famous thirteen page article 'Molecules' in the September issue of Nature.^[3] In the opening section to this article, Maxwell clearly states: Chemical structure of benzene Selfmade by cacycle File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Chemical structure of benzene Selfmade by cacycle File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Benzene, also known as benzol, is an organic chemical compound with the formula C6H6. ... Covalent bonding is a form of chemical bonding characterized by the sharing of one or more pairs of electrons between atoms, in order to produce a mutual attraction, which holds the resultant molecule together. ... James Clerk Maxwell (13 June 1831 – 5 November 1879) was a Scottish mathematical physicist, born in Edinburgh. ...

An atom is a body which cannot be cut in two; a molecule is the smallest possible portion of a particular substance.

After speaking about the atomic theory of Democritus, Maxwell goes on to tell us that the word 'molecule' is a modern word. He states, "it does not occur in Johnson's Dictionary. The ideas it embodies are those belonging to modern chemistry." We are told that an 'atom' is a material point, invested and surrounded by 'potential forces' and that when 'flying molecules' strike against a solid body in constant succession it causes what is called pressure of air and other gases. At this point, however, Maxwell notes that no one has ever seen or handled a molecule. Image File history File links Cquote1. ... Image File history File links Cquote2. ... Various atoms and molecules as depicted in John Daltons A New System of Chemical Philosophy (1808). ... ‎ Democritus (Greek: Δημόκριτος) was a pre-Socratic Greek philosopher (born at Abdera in Thrace around 460 BC[1][2]). Democritus was a student of Leucippus and co-originator of the belief that all matter is made up of various imperishable, indivisible elements which he called atomos, from which we get the... The use of water pressure - the Captain Cook Memorial Jet in Lake Burley Griffin, Canberra. ...

In 1894, Emil Fischer postulated the famous "Lock and Key" molecule bonding theory. According to this theory, molecules fit together according to complementary geometric shape. Enzymes, for example, are very specific, and Fischer suggested that this was because both the enzyme and the substrate possess specific complementary geometric shapes that fit exactly into one another.^[4] This is often referred to as "the lock and key" model. An enzyme combines with its substrate(s) to form a short-lived enzyme-substrate complex. However, while this model explains enzyme specificity, it fails to explain the stabilization of the transition state that occurs. Hermann Emil Fischer (October 9, 1852 - July 15, 1919) was a German chemist and recipient of the Nobel Prize for Chemistry in 1902. ...

The induced fit hypothesis model of enzyme action (a "lock-and-key" model).

Later, Fisher developed the Fisher projection technique for viewing 3-D molecules on a 2-D sheet of paper: Image File history File links Induced_fit_diagram. ... Image File history File links Induced_fit_diagram. ...

,

Image File history File links Fischer_projection. ... Image File history File links Fischer_Projection2. ...

20th century

In the early 1900s, the American chemist Gilbert Lewis began to use dots in lecture, while teaching undergraduates at Harvard, to represent the electrons around atoms. His students favored these drawings, which stimulated him in this direction. From these lectures, Lewis noted that elements with a certain number of electrons seemed to have a special stability. To Lewis it appeared that once a core of eight electrons has formed around a nucleus, the layer is filled, and a new layer is started. Lewis also noted that various ions with eight electrons also seemed to have a special stability. On these views, he proposed the rule of eight or octet rule: Ions or atoms with a filled layer of eight electrons have a special stability.^[5] Lewis in the Berkeley Lab Gilbert Newton Lewis (October 23, 1875-March 23, 1946) was a famous physical chemist. ... Harvard University is a private university in Cambridge, Massachusetts, USA, and a member of the Ivy League. ... An ion is an atom or group of atoms that normally are electrically neutral and achieve their status as an ion by loss (or addition) of (an) electron(s). ... The bonding in carbon dioxide The octet rule is a simple chemical rule of thumb that states that atoms tend to combine in such a way that they each have eight electrons in their valence shells, similar to the electronic configuration of a noble gas. ...

Moreover, noting that a cube has eight corners Lewis envisioned an atom as having eight sides available for electrons, like the corner of a cube. Subsequently, in 1902 he devised a conception in which cubic atoms can bond on their sides to form cubic-structured molecules:

Gilbert Lewis' notes showing the possible "cubic" arrangement of electrons about an atom. (1902)

In other words, electron-pair bonds are formed when two atoms share an edge, as in structure C below. This results in the sharing of two electrons. Similarly, charged ionic-bonds are formed by the transfer of an electron from one cube to another, without sharing an edge A. An intermediate state B where only one corner is shared was also postulated by Lewis. Lewis in the Berkeley Lab Gilbert Newton Lewis (October 23, 1875-March 23, 1946) was a famous physical chemist. ...

Lewis cubic-atoms bonding to form cubic-molecules

Hence, double bonds are formed by sharing a face between two cubic atoms. This results in the sharing of four electrons: Covalent bonding is a form of chemical bonding characterized by the sharing of one or more pairs of electrons between atoms, in order to produce a mutual attraction, which holds the resultant molecule together. ...

Lewis cubic-molecules

About ten years later, while working as the chair of the department of chemistry at the University of California, Berkeley, Lewis read a paper by an English graduate student, Alfred Parson, who was visiting Berkeley for a year. In this paper, Parson suggested that a chemical bond results from two electrons being shared between two atoms. This, according to Lewis, meant that bonding occurred when two electrons formed a shared edge between two complete cubes. The University of California, Berkeley (also known as UC Berkeley, Berkeley, Cal, and by other names, see below) is the oldest and flagship campus of the ten-campus University of California system. ... A chemical bond is the physical phenomenon (or phenomena) responsible for the attractive interactions betwen atoms that confers stability to di- and polyatomic chemical compounds. ...

On these views, in his famous 1916 article The Molecule and the Atom, Lewis introduced the “Lewis structure” to represent atoms and molecules, where dots represent electrons and lines represent covalent bonds. Moreover, he proposed that an atom tended to form an ion by gaining or losing the number of electrons needed to complete a cube. Thus, Lewis structures show each atom in the structure of the molecule using its chemical symbol. Lines are drawn between atoms that are bonded to one another; occasionally, pairs of dots are used instead of lines. Excess electrons that form lone pairs are represented as pair of dots, and are placed next to the atoms on which they reside: The Electron is a fundamental subatomic particle that carries an electric charge. ... This article does not cite its references or sources. ...

Lewis dot structures of the Nitrite-ion

To summarize his views on his new bonding model, Lewis states: ^[6] Image File history File links Download high resolution version (1100x297, 8 KB) File links The following pages link to this file: Lewis structure User:Benjah-bmm27/Gallery ... Image File history File links Download high resolution version (1100x297, 8 KB) File links The following pages link to this file: Lewis structure User:Benjah-bmm27/Gallery ...

Two atoms may conform to the rule of eight, or the octet rule, not only by the transfer of electrons from one atom to another, but also by sharing one or more pairs of electrons...Two electrons thus coupled together, when lying between two atomic centers, and held jointly in the shells of the two atoms, I have considered to be the chemical bond. We thus have a concrete picture of that physical entity, that "hook and eye" which is part of the creed of the organic chemist.

The following year, in 1917, an unknown American undergraduate chemical engineer named Linus Pauling was learning the Dalton hook-and-eye bonding method at the Oregon Agricultural College, which was the vogue description of bonds between atoms at the time. Each atom had a certain number of hooks that allowed it to attach to other atoms, and a certain number of eyes that allowed other atoms to attach to it. A chemical bond resulted when a hook and eye connected. Pauling, however, wasn't satisfied with this archaic method and looked to the newly-emerging field of quantum physics for a new method. Image File history File links Cquote1. ... Image File history File links Cquote2. ... Linus Carl Pauling (February 28, 1901 – August 19, 1994) was an American quantum chemist and biochemist. ... Oregon State University (OSU) is a four-year research and degree-granting public university, located in Corvallis, Oregon in the United States. ... Fig. ...

Subsequently, in 1931, building on theories found in Lewis' famous article, Pauling published his ground-breaking article "The Nature of the Chemical Bond" (see: article) in which he used quantum mechanics to calculate properties and structures of molecules, such as angles between bonds and rotation about bonds. On these concepts, Lewis developed hybridization theory to account for bonds in molecules such as CH₄, in which four sp³ hybridised orbitals are overlapped by hydrogen's 1s orbital, yielding four sigma (σ) bonds. The four bonds are of the same length and strength, which yields a molecular structure as shown below: Fig. ... General Name, Symbol, Number hydrogen, H, 1 Chemical series nonmetals Group, Period, Block 1, 1, s Appearance colorless Atomic mass 1. ... Electron atomic and molecular orbitals, showing among others the sigma bond of two s-orbitals and a sigma bond of two p-orbitals In chemistry, sigma bonds (σ bonds) are a type of covalent chemical bond. ...

translates into

Owing to these exceptional theories, Pauling has been the only person to ever win two unshared Nobel prizes My feeble attempt at drawing methane in terms of hybrid orbitals File links The following pages link to this file: Orbital hybridisation Categories: GFDL images ... My feeble attempt at drawing methane in terms of structure File links The following pages link to this file: Orbital hybridisation Categories: GFDL images ... Nobel Prize medal. ...

In 1937, chemist K.L. Wolf introduced the concept of supermolecules (Übermoleküle) to describe hydrogen bonding in acetic acid dimers. Supermolecules are organized polymolecular systems, held together by non-covalent interactions. Examples of a supermolecules are the Cyclodextrins, which have a cavity in which a guest molecule can fit: In chemistry supermolecules are well defined discrete oligo-molecular species formed via association of a finite number of constituents. ... In chemistry, a hydrogen bond is a type of attractive intermolecular force that exists between two partial electric charges of opposite polarity. ... Acetic acid, also known as ethanoic acid, is an organic chemical compound best recognized for giving vinegar its sour taste and pungent smell. ... Sucrose, or common table sugar, is composed of glucose and fructose. ... Chemical structure of the three main types of cyclodextrins. ...

Supermolecules - chemical structure of the three main types of cyclodextrins.

In the mid-twentieth century, neurochemists began to discover molecules that have function in human brain activity. In 1948, for example, Maurice M. Rapport isolated and named the now-famous structure “serotonin”. In the central nervous system, serotonin is believed to play an important role in the regulation of mood, sleep, emesis, sexuality, and appetite. By many accounts, serotonin is considered the “confidence chemical”, in that, for example, cerebral levels of this neurochemical are higher in alpha-males and alpha-females, such as captains, group leaders, and high-ranking chimpanzees in troop hierarchies. Moreover, during the first six months of being in love, paradoxically, serotonin levels in couples drop to 40 percent below those in normal subjects: Image File history File links Cyclodextrin. ... Image File history File links Cyclodextrin. ... In chemistry supermolecules are well defined discrete oligo-molecular species formed via association of a finite number of constituents. ... Cyclodextrins are cyclic oligomers of glucose which typically contain 6-8 monomers in a ring. ... Serotonin (5-hydroxytryptamine, or 5-HT) is a monoamine neurotransmitter synthesized in serotonergic neurons in the central nervous system (CNS) and enterochromaffin cells in the gastrointestinal tract. ... A diagram showing the CNS: 1. ... Mood may refer to: chese Grammatical mood Emotional mood This is a disambiguation page, a list of pages that otherwise might share the same title. ... Sleep is the state of natural rest observed in most mammals, birds, fish, as well as invertebrates such as the fruitfly Drosophila. ... Vomiting (or emesis) is the forceful expulsion of the contents of ones stomach through the mouth. ... This article is about sex acts and practices (i. ... The appetite is the desire to eat food, felt as hunger. ...

Molecular-structure of serotonin (1948) Image File history File links Download high resolution version (2000x1431, 33 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Serotonin ... Serotonin (5-hydroxytryptamine, or 5-HT) is a monoamine neurotransmitter synthesized in serotonergic neurons in the central nervous system (CNS) and enterochromaffin cells in the gastrointestinal tract. ...

3D-structure of serotonin C10H12N2O Image File history File links Download high-resolution version (1100x831, 185 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Serotonin History of the molecule ...

In 1953, American scientists James Watson and Francis Crick determined the molecular structure of DNA or “deoxyribonucleic acid”, which consists of a pair of molecules, organized as strands running start-to-end and joined by hydrogen bonds along their lengths.^[7] Each strand is a chain of chemical "building blocks", called nucleotides, of which there are four types: adenine (abbreviated A), cytosine (C), guanine (G) and thymine (T).^[7] These molcular strands links together in the form a spiral structure, as shown below: There is more than one person with the name James Watson: James Watson, participant in the Battle of the Little Bighorn James Watson, author of the novel Talking in Whispers James Watson, U.S. Senator from New York (1797-1801) James Watson, painter of 77 portraits held by the U... Francis Harry Compton Crick OM (8 June 1916 – 28 July 2004) was an English physicist, molecular biologist and neuroscientist, most noted for being one of the co-discoverers of the structure of the DNA molecule in 1953. ... The general structure of a section of DNA Deoxyribonucleic acid (DNA) is a nucleic acid that contains the genetic instructions for the biological development of a cellular form of life or a virus. ... In chemistry, a molecule is an aggregate of at least two atoms in a definite arrangement held together by special forces. ... Snapshot from a simulation of liquid water. ... A nucleotide is a chemical compound that consists of a heterocyclic base, a sugar, and one or more phosphate groups. ... Adenine is one of the two purine nucleobases used in forming nucleotides of the nucleic acids DNA and RNA. In DNA, adenine binds to thymine via two hydrogen bonds to assist in stabilizing the nucleic acid structures. ... Cytosine is one of the 5 main nucleobases used in storing and transporting genetic information within a cell in the nucleic acids DNA and RNA. It is a pyrimidine derivative, with a heterocyclic aromatic ring and two substituents attached (an amine group at position 4 and a keto group at... Guanine is one of the five main nucleobases found in the nucleic acids DNA and RNA; the others being adenine, cytosine, thymine, and uracil. ... For the similarly-spelled vitamin compound, see Thiamine Thymine, also known as 5-methyluracil, is a pyrimidine nucleobase. ...

In 1958, the American biochemist George Wald and his co-workers discovered that a photosensitive molecule in the rod cells of the eye, called retinal C₂₀H₂₈O, straightens its configuration in response to light, i.e. photons. This straightened configuration results to trigger a nerve impulse; statistically it takes five photons to trigger such a nerve impulse. This is the core mechanism of the vision process: Image File history File links ADN_animation. ... The general structure of a section of DNA Deoxyribonucleic acid (DNA) is a nucleic acid that contains the genetic instructions for the biological development of a cellular form of life or a virus. ... George Wald (November 18, 1906–April 12, 1997) was an American scientist who is best known for his work with pigments in the retina. ... In the vision system, retinal, technically called retinene1 or retinaldehyde, is a light-sensitive retinene molecule found in the photoreceptor cells of the retina. ... The word light is defined here as electromagnetic radiation of any wavelength; thus, X-rays, gamma rays, ultraviolet light, microwaves, radio waves, and visible light are all forms of light. ... The word light is defined here as electromagnetic radiation of any wavelength; thus, X-rays, gamma rays, ultraviolet light, microwaves, radio waves, and visible light are all forms of light. ...

Retinal molecule - straightens in response to a photon γ (light), of the correct wavelength

For his work, Wald won a share of the 1967 Nobel Prize in Physiology or Medicine with Haldan Keffer Hartline and Ragnar Granit. Image File history File links Download high-resolution version (1040x555, 9 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Photon Retinal User talk:V8rik History of the molecule User:Sadi Carnot/Sandbox2 ... Image File history File links Download high-resolution version (1040x555, 9 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Photon Retinal User talk:V8rik History of the molecule User:Sadi Carnot/Sandbox2 ... The word light is defined here as electromagnetic radiation of any wavelength; thus, X-rays, gamma rays, ultraviolet light, microwaves, radio waves, and visible light are all forms of light. ... 1967 (MCMLXVII) was a common year starting on Sunday of the Gregorian calendar (the link is to a full 1967 calendar). ... List of Nobel Prize laureates in Physiology or Medicine from 1901 to the present day. ... Haldan Keffer Hartline (December 22, 1903 - March 17, 1983) was an American physiologist who was a cowinner (with George Wald and Ragnar Granit) of the 1967 Nobel Prize in Physiology or Medicine for his work in analyzing the neurophysiological mechanisms of vision. ... Ragnar Arthur Granit (October 30, 1900, Helsinki, Finland - March 12, 1991, Stockholm, Sweden) was a Finnish scientist who won the Nobel Prize in Physiology or Medicine in 1967, along with Haldan Keffer Hartline and George Wald. ...

During the later half of the twentieth century, computer technologies began to increase; this led to the determination of larger molecular structures such as proteins. In 1958, for example, the structure of the myoglobin molecule was determined using X-ray crystallography by Max Perutz and Sir John Cowdery Kendrew, as shown below, where the colored segments are alpha helices: ^[8] A representation of the 3D structure of myoglobin, showing coloured alpha helices. ... Myoglobin is a single-chain protein of 153 amino acids, containing a heme (iron-containing porphyrin) group in the center. ... X-ray crystallography is a technique in crystallography in which the pattern produced by the diffraction of X-rays through the closely spaced lattice of atoms in a crystal is recorded and then analyzed to reveal the nature of that lattice. ... Max Ferdinand Perutz, OM (May 19, 1914 – February 6, 2002) was an Austrian-British molecular biologist. ... This article or section does not cite its references or sources. ... A diagram of the alpha helix structure of amino acids In proteins, the α helix is a major structural motif in secondary structure. ...

A representation of the 3D structure of myoglobin molecule (1958)

Perutz and Kendrew received the Nobel Prize in Chemistry for determining the structure of this molecule. Download high resolution version (695x702, 67 KB)Image created by uploader from PDB file: Source: Sperm whale (Physeter catodon) Authors: S.E.V. Phillips Reference: Structure and refinement of oxymyoglobin at 1. ... Download high resolution version (695x702, 67 KB)Image created by uploader from PDB file: Source: Sperm whale (Physeter catodon) Authors: S.E.V. Phillips Reference: Structure and refinement of oxymyoglobin at 1. ... Myoglobin is a single-chain protein of 153 amino acids, containing a heme (iron-containing porphyrin) group in the center. ... This is a list of Nobel Prize laureates in Chemistry from 1901 to 2006. ...

In 1985, Harold Kroto of the University of Sussex, and James Heath, Sean O'Brien, Robert Curl and Richard Smalley, from Rice University, discovered C₆₀ or what is famously known as a "buckyball": Sir Harold Walter Kroto KBE , FRS , Ph. ... The University of Sussex is an English campus university located near the East Sussex village of Falmer, near Brighton and Hove. ... As the front man and lead guitar player of The Reverend Horton Heat trio, James (JIM) Heath is regarded as the best phycobilly guitar player out of texas. ... Sean OBrien may refer to: Sean OBrien (writer) Sean OBrien (politician), member of the South Dakota State House of Representatives This human name article is a disambiguation page — a list of pages that might otherwise share the same title, which is a persons or persons name. ... Robert Floyd Curl, Jr. ... Richard Errett Smalley Richard Errett Smalley (June 6, 1943 – October 28, 2005) was the Gene and Norman Hackerman Professor of Chemistry and a Professor of Physics and Astronomy at Rice University, in Houston, Texas. ... Lovett Hall William Marsh Rice University, commonly called Rice University and opened in 1912 as Rice Institute, is a private research university located near the Museum District and adjacent to the Texas Medical Center in Houston, Texas. ...

Buckminsterfullerene C₆₀ - a spherical 60-carbon atom molecule

In molecular beam experiments, discrete peaks were observed corresponding to molecules with the exact mass of sixty or seventy or more carbon atoms. Shortly thereafter came the discover the fullerenes. Kroto, Curl, and Smalley were awarded the 1996 Nobel Prize in Chemistry for their roles in the discovery of this class of compounds. C₆₀. Other fullerenes were later noticed occurring outside of a laboratory environment, e.g., such as in normal candle soot. Image File history File links Download high resolution version (672x623, 147 KB)A 3D model of a C60 molecule, also called a Buckyball. Created by Michael Ströck (mstroeck) on February 6, 2006 in iMol for Mac OS X and Photoshop CS2. ... Image File history File links Download high resolution version (672x623, 147 KB)A 3D model of a C60 molecule, also called a Buckyball. Created by Michael Ströck (mstroeck) on February 6, 2006 in iMol for Mac OS X and Photoshop CS2. ... Mass spectrometry is a technique for separating ions by their mass-to-charge (m/z) ratios. ... The fullerenes are a recently-discovered family of carbon allotropes named after Buckminster Fuller. ... This is a list of Nobel Prize laureates in Chemistry from 1901 to 2006. ... A collection of lit candles on ornate candlesticks A close-up image of a candle showing the wick and the various regions of the flame. ... Soot, also called lampblack, Pigment Black 7, carbon black or black carbon, is a dark powdery deposit of unburned fuel residues, usually composed mainly of amorphous carbon, that accumulates in chimneys, automobile mufflers and other surfaces exposed to smoke—especially from the combustion of carbon-rich organic fuels in the...

In 1999, researchers from the University of Vienna demonstrated that the wave-particle duality applied to macro-molecules such as fullerene.^[9] 1999 (MCMXCIX) was a common year starting on Friday, and was designated the International Year of Old Farts by the Sometimes-United Nations. ... Representation of a university class, 1350s. ... Inhabitants according to official census figures: 1800 to 2005 Vienna in 1858 UN complex in Vienna, with the non-affiliated Austria Center Vienna in front - picture taken from Danube Tower in nearby Danube Park. ... In physics, wave-particle duality holds that light and matter exhibit properties of both waves and of particles. ...

21st century

On the cutting edge is nanotechnology, which is the science and engineering of matter at the atomic scale. In other words, recent areas of interest in the molecular world have been to build functionable molecules atom-by-atom, such as, for example, a molecular gear: Molecular gears from a NASA computer simulation. ...

Molecular gears from a NASA computer simulation.

In this direction, for example, in June of 2004 scientists from China's Tsinghua University and Louisiana State University demonstrated the use of nanotubes in incandescent lamps, replacing a tungsten filament in a lightbulb with a carbon nanotube one: Image File history File links Molecular_gears. ... Image File history File links Molecular_gears. ... NASA Insignia Listen to this article · (info) This audio file was created from an article revision dated 2005-09-01, and does not reflect subsequent edits to the article. ... Tsinghua University, (Simplified Chinese: , Traditional Chinese: ; pinyin: Qinghuá Dàxué) is a university in Beijing, China. ... Louisiana State University and Agricultural and Mechanical College, generally known as Lousiana State University or LSU, is a public, coeducational university located in Baton Rouge, Louisiana and the main campus of the Louisiana State University System. ... An electronic device known as a diode can be formed by joining two nanoscale carbon tubes with different electronic properties. ... The incandescent light bulb uses a glowing wire filament heated to white-hot by electrical resistance, to generate light (a process known as thermal radiation). ... General Name, Symbol, Number tungsten, W, 74 Chemical series transition metals Group, Period, Block 6, 6, d Appearance grayish white, lustrous Atomic mass 183. ... Filaments surrounding a solar flare, caused by the interaction of the plasma in the Suns atmopshere with its magnetic field. ... The incandescent light bulb uses a glowing wire filament heated to white-hot by electrical resistance, to generate light (a process known as thermal radiation). ...

3D-structure of a carbon nanotube molecule.

In September of 2005, a research team, led by Ludwig Bartel at the University of California Riverside designed a molecule that walks over a surface like a human, i.e. a walking molecule.^[10] The molecule, 9,10-dithioanthracene or “DTA”, has two linkers that act as feet. With a source of thermal energy, the molecule moves such that only one of the linkers is lifted from the surface while the other stabilizes the molecule and guides its motion. By alternating its two feet, the nano-walker is able to move over atomic surfaces without the assistance of nano-rails or atomic-groves. Image File history File links Kohlenstoffnanoroehre_Animation. ... Image File history File links Kohlenstoffnanoroehre_Animation. ... The University of California, Riverside, is a public coeducational university whose main campus is in a suburban district of the city of Riverside, California. ... To meet Wikipedias quality standards, this article or section may require cleanup. ...

Similarly, in October of 2005, researchers at Rice University designed the world's first molecular car.^[11] With a wheelbase of less than 5 nm, the tiny atom-sized car was driven on a gold-plated microscopic highway. The wheels were buckyballs, spheres of pure carbon containing 60 atoms a piece. According to these researchers, this "nanocar" represents the first step towards molecular manufacturing. Lovett Hall William Marsh Rice University, commonly called Rice University and opened in 1912 as Rice Institute, is a private research university located near the Museum District and adjacent to the Texas Medical Center in Houston, Texas. ...

The modern theory of molecules makes great use of the many numerical techniques offered by computational chemistry. At the forefront of chemical astronomy, hundreds of molecules have now been identified in interstellar space by microwave spectroscopy. Computational chemistry is a branch of chemistry that uses the results of theoretical chemistry incorporated into efficient computer programs to calculate the structures and properties of molecules and solids, applying these programs to real chemical problems. ... This is a list of molecules that have been detected in the interstellar medium as of 2003. ... The distribution of ionized hydrogen (known by astronomers as H II (aitch two) from old spectroscopic terminology) in the parts of the Galactic interstellar medium visible from the Earths northern hemisphere (from the Wisconsin H-Alpha Mapper Survey) In astronomy, the interstellar medium (or ISM) is the matter (interstellar... Rotational spectroscopy or microwave spectroscopy studies the absorption and emission of electromagnetic radiation (typically in the microwave region of the electromagnetic spectrum) by molecules associated with a corresponding change in the rotational quantum number of the molecule. ...

See also

• History of chemistry
• History of thermodynamics
• History of molecular biology
• Kinetic theory

Portrait of Monsieur Lavoisier and his Wife, by Jacques-Louis David The history of chemistry may be said to begin with the distinction of chemistry from alchemy by Robert Boyle in his work The Skeptical Chymist, which was written after a long and tearfilled talk with his father, and alchymist... Savery Engine [1698] The history of thermodynamics is a core strand in the history of physics and an important one in the history of science. ... -1... Kinetic theory attempts to explain macroscopic properties of gases, such as pressure, temperature, or volume, by considering their molecular composition and motion. ...

References

1. ^ Avogadro, Amedeo (1811). "Masses of the Elementary Molecules of Bodies", Journal de Physique, 73, 58-76
2. ^ Bader, A. & Parker, L. (2001). "Joseph Loschmidt", Physics Today, Mar.
3. ^ Maxwell, James Clerk, "Molecules". Nature, September, 1873.
4. ^ Fischer E. (1894). "Einfluss der Configuration auf die Wirkung der Enzyme". Ber. Dt. Chem. Ges. 27: 2985-2993.
5. ^ Cobb, Cathy (1995). Creations of Fire - Chemistry's Lively History From Alchemy to the Atomic Age. Perseus Publishing. ISBN 073820594X.
6. ^ "Valence and The Structure of Atoms and Molecules", G. N. Lewis, American Chemical Society Monograph Series, page 79 and 81.
7. ^ ^{a b} Butler, John M. (2001) Forensic DNA Typing "Elsevier". pp. 14-15. ISBN 012147951X.
8. ^ Kendrew JC, Bodo G, Dintzis HM, Parrish RG, Wyckoff H, Phillips DC. (1958). A three-dimensional model of the myoglobin molecule obtained by x-ray analysis. Nature 181(4610):662-6.
9. ^ Arndt, M., O. Nairz, J. Voss-Andreae, C. Keller, G. van der Zouw, A. Zeilinger (14 October 1999). "Wave-particle duality of C60". Nature 401: 680-682.
10. ^ Pittalwala, M. (2005). "Molecule Walks Like a Human", Sept., Source: UCR Newsroom, Sept. 26
11. ^ Lamba, R. (2005). "Scientist Build World's First Molecular Car", Oct. Source: physOrg.com

Anton Zeilinger Anton Zeilinger (born on 20 May 1945 in Ried im Innkreis, Austria) is a professor of physics at the University of Vienna, previously Innsbruck. ...

Further reading

• Partington, J.R. (1989). A Short History of Chemistry. Dover Publications, Inc. ISBN 0486659771.
• Pert, Candace (1997). Molecules of Emotion. Touchstone Books. ISBN 0684846349.
• Atkins, Peter (2003). Atkins' Molecules, 2nd Ed. Cambridge University Press. ISBN 0521535360.
• Sargent, Ted (2006). The Dance of Molecules - How Nanotechnology is Changing our Lives. Thunder's Mouth Press. ISBN 1560258098.

External links

• Geometric Structures of Molecules - Middlebury College
• Atoms and Molecules - McMaster University
• Molecular Evolution Table - Institute of Human Thermodynamics
• 3D Molecule Viewer - The Wileys Family
• Molecule of the Month - School of Chemistry, University of Bristol

Types

• Antibody Molecule - The National Health Museum
• Human Molecule, Earth Molecule, and Sun Molecule - Institute of Human Thermodynamics
• 15 Types of Molecules - IUPAC Definitions

Definitions

• Molecule Definition - Frostburg State University (Department of Chemistry)
• Definition of Molecule - IUPAC

Articles

• Molecules Used to Make Nano-sized Containers - TRN Newswire
• Molecular Computer Processors - HP Labs